Since the Mideast conflict is so messed up, why stop with Balfour? The PA should also sue Britain and France (for the the 1916 Sykes-Picot agreement), Britain and the Husseini family (for the 1922 Cairo Conference, which led to the creation of an independent Transjordan), and the UN (for the 1948 Partition Plan). The Palestinians can even sue themselves for signing the 1993 Oslo accords . . .
See also Dan Margalit‘s take.